WO2021194189A1 - Method for manufacturing composite non-woven fabric, composite non-woven fabric, and article - Google Patents

Abstract

Disclosed is a method for manufacturing a composite non-woven fabric, a composite non-woven fabric, and an article. The disclosed method for manufacturing a composite non-woven fabric comprises the steps of: continuously forming a first spunbond non-woven fabric layer (S10); continuously forming a melt blown non-woven fabric layer on the first spunbond non-woven fabric layer (S20); and continuously forming a second spunbond non-woven fabric layer on the melt blown non-woven fabric layer (S30), wherein the step of continuously forming a melt blown non-woven fabric layer (S20) comprises the steps of: continuously forming free fibers with a non-conductive polymer (S20-1); continuously spinning the free fibers (S20-2); continuously charging the free fibers by continuously spraying a polar solvent onto the free fibers (S20-3); and continuously forming the non-woven fabric by continuously collecting the free fibers (S20-4).

Description

Method for manufacturing composite nonwoven fabric, composite nonwoven fabric and article

A method of making a composite nonwoven fabric, a composite nonwoven fabric, and an article are disclosed. More specifically, a method for manufacturing a composite nonwoven fabric capable of producing a composite nonwoven fabric having excellent retention of fine dust removal performance, a composite nonwoven fabric, and an article are disclosed.

In the case of a mask for removing fine dust, it is composed of an inner and outer skin material and a filter material that filters fine dust in the center in multiple layers.

As the filter layer, a melt-blown nonwoven fabric that has been treated is mainly used. Meltblown nonwoven fabric has low shape stability due to low mechanical strength and high flexibility, so structural deformation easily occurs due to external impact or friction. Therefore, in order to protect the melt-blown non-woven fabric layer and provide shape stability, a mask is formed by laminating a non-woven fabric having high mechanical properties such as shape stability and tensile strength on both sides or one side of the melt-blown non-woven fabric layer, mainly spunbond. The nonwoven fabric is laminated through a separate laminating process.

In addition, the spunbond nonwoven fabric, which is generally applied as an inner and outer skin material on one or both sides of the electrostatically treated meltblown material, has only a function of imparting shape stability with little fine dust removal efficiency because the filaments are thick and the pores are large. Therefore, among the multi-layered mask nonwoven fabric composition, since fine dust is filtered only in the filter layer located in the central part, there is a problem in that the fine dust is intensively stacked on the filter layer, so that the filtering efficiency decreases with time of use. In some countries, these issues may also affect the respiratory safety of users.

In addition, since the nonwoven fabric used as the inner and outer skin layer is mainly laminated by ultrasonic welding along the outline of the mask, the structure of the meltblown nonwoven fabric charged with the inner layer during the fusion process is changed, so that the filtering performance may be deteriorated.

One embodiment of the present invention provides a method for manufacturing a composite nonwoven fabric capable of producing a composite nonwoven fabric having excellent retention of fine dust removal performance.

Another embodiment of the present invention provides a composite nonwoven fabric prepared by the method for manufacturing the composite nonwoven fabric.

Another embodiment of the present invention provides an article comprising the composite nonwoven fabric.

One aspect of the present invention is

Continuously forming a first spunbond nonwoven layer (S10);

continuously forming a melt blown nonwoven fabric layer on the first spunbond nonwoven fabric layer (S20); and

and continuously forming a second spunbond nonwoven layer on the melt blown nonwoven fabric layer (S30),

The melt blown nonwoven fabric layer continuous forming step (S20),

Continuously forming free fibers with a non-conductive polymer (S20-1),

Continuously spinning the free fiber (S20-2),

Continuously charging the free fibers by continuously spraying a polar solvent on the free fibers (S20-3) and

It provides a method of manufacturing a composite nonwoven fabric comprising the step of continuously forming the nonwoven fabric by continuously integrating the free fibers (S20-4).

The free fiber charging step (S20-3) may be performed by continuously spraying the polar solvent together with a gas.

The injection pressure of the gas may be 0.5-4 bar based on the injection pressure of the polar solvent of 1 bar.

The manufacturing method of the composite nonwoven fabric may not include a separate drying step for removing the polar solvent sprayed in the free fiber continuous charging step (S20-3).

The polar solvent continuously sprayed in the free fiber continuous charging step (S20-3) may be continuously heated and evaporated by heated air within a DCD (die to collector distance) section of the composite nonwoven fabric manufacturing apparatus.

The manufacturing method of the composite nonwoven fabric comprises the steps of continuously thermocompressing the first spunbonded nonwoven fabric layer, the meltblown nonwoven fabric layer and the second spunbonded nonwoven fabric layer after the melt blown nonwoven fabric layer forming step (S20) ( S40) may be further included.

Another aspect of the present invention is

It provides a composite nonwoven fabric manufactured by the method for manufacturing the composite nonwoven fabric.

Another aspect of the present invention is

An article comprising the composite nonwoven fabric is provided.

The article may be a mask for removing fine dust, a filter for an air purifier, or a filter for an air conditioner.

The method of manufacturing a composite nonwoven fabric according to an embodiment of the present invention may improve the retention of fine dust removal performance.

In addition, the composite nonwoven fabric manufactured by the manufacturing method of the composite nonwoven fabric may be utilized for the purpose of removing various kinds of dust, fine dust, bacteria, etc., and may be used as a medical or health mask.

1 is a view schematically showing a composite nonwoven fabric according to an embodiment of the present invention.

2 is a view schematically showing an apparatus for manufacturing a composite nonwoven used to continuously manufacture a composite nonwoven according to an embodiment of the present invention.

Hereinafter, a method for manufacturing a composite nonwoven fabric according to an embodiment of the present invention will be described in detail.

In the present specification, "non-woven fabric composite" is not a non-woven fabric laminate manufactured through a separate lamination (lamination) post-process after two or more kinds of non-woven fabrics are individually prepared, but two or more kinds of non-woven fabrics are one It refers to a nonwoven fabric manufactured by a continuous process and integrated. A "composite non-woven fabric" may also be referred to as a "monolithic non-woven fabric". The composite nonwoven fabric has a strong interlayer bonding and excellent morphological stability and filtration performance compared to the nonwoven fabric laminate.

In addition, in the present specification, the "electrostatically treated melt blown nonwoven sub-layer" may be manufactured by a continuous process. Specifically, the "electrostatically treated melt blown nonwoven sub-layer" may be manufactured by sequentially or simultaneously performing "preparation of melt blown nonwoven fabric" and "charge treatment" in a continuous process.

The method for manufacturing a composite nonwoven fabric according to an embodiment of the present invention includes the steps of continuously forming a first spunbonded nonwoven layer (S10) and continuously forming a melt blown nonwoven layer on the first spunbonded nonwoven layer ( S20).

The first spunbond non-woven fabric layer continuous forming step (S10) is melt-extruding, cooling and stretching a thermoplastic non-conductive polymer to form a fiber yarn, and then stacking the fiber yarn on a screen belt to form a web (web forming) it could be

In the continuous formation of the melt blown nonwoven layer (S20), a thermoplastic non-conductive polymer (charge increasing agent can be added) is melt-extruded, hot air drawn, and cooled to form a fiber yarn, and then the fiber yarn is subjected to the first spunbond. In the continuous forming step (S10) of the nonwoven layer, it may be laminated on the web-formed spunbond to form a web.

Specifically, the continuous formation of the melt blown nonwoven layer (S20) includes the steps of continuously forming free fibers with a non-conductive polymer (S20-1), continuously spinning the free fibers (S20-2), and Continuously spraying a polar solvent (for example, water) onto the free fibers to continuously charge the free fibers (S20-3) and continuously integrating the free fibers to continuously form a melt-blown nonwoven fabric (S20-4) may be included.

The non-conductive polymer used in each of the first spunbond nonwoven fabric layer continuous forming step (S10) and the melt blown nonwoven fabric layer continuous forming step (S20) is polyolefin, polystyrene, polycarbonate, polyester, polyamide, and their copolymers or combinations thereof.

The polyolefin may include polyethylene, polypropylene, poly-4-methyl-1-pentene, polyvinyl chloride, or a combination thereof.

The polyester may include polyethylene terephthalate, polylactic acid, or a combination thereof.

The non-conductive polymer may further include an additive.

The additives may include pigments, light stabilizers, primary antioxidants, secondary antioxidants, metal deactivators, hindered amines, hindered phenols, fatty acid metal salts, triester phosphites, phosphates, fluorine-containing compounds, nucleating agents, or combinations thereof. may include

Also, in one embodiment, the antioxidant may function as a charge enhancer. Possible charge enhancers include thermally stable organic triazine compounds, oligomers or combinations thereof, which compounds or oligomers may further contain at least one nitrogen atom in addition to the nitrogen in the triazine ring.

For example, charge increasing agents for the purpose of improving charging characteristics are disclosed in US Patent Nos. 6,268,495, 5,976,208, 5,968,635, 5,919,847, and 5,908,598. For example, the charge increasing agent may include a hindered amine-based additive, a triazine additive, or a combination thereof.

As another example, the charge increasing agent is poly[((6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl)((2, 2,6,6-tetramethyl-4-piperidyl)imino)hexamethylene ((2,2,6,6-tetramethyl-4-piperidyl)imino)] (manufactured by BASF, CHIMASSORB 944) 1,6-hexanediamine-N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl with (2,4,6-trichloro-1,3,5-triazine) )-polymer, N-butyl-1-butanamine, reaction product with N-butyl-2,2,6,6-tetramethyl-4-piperidinamine) (manufactured by BASF, CHIMASSORB 2020) or a combination thereof may include.

The charge increasing agent is an N-substituted amino aromatic compound, in particular a tri-amino substituted compound such as 2,4,6-trianilino-p-(carbo-2′-ethylhexyl-1′-oxy)- 1,3,5-triazine (manufactured by BASF, UVINUL T-150) may be used. Other charge enhancers include 2,4,6-tris-(octadecylamino)-triazine, also known as tristearyl melamine ("TSM"), alpha-alkenes (C20-C24) maleic anhydride-4-amino-2 ,2,6,6-tetramethylpiperidine (manufactured by BASF, Uvinul 5050H) and a mixture of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol (manufactured by BASF, Tinuvin 622SF) are available.

The content of the charge increasing agent may be 0.25 to 5 parts by weight based on 100 parts by weight of the total weight of each electrostatically treated melt blown nonwoven fabric. If the content of the charge increasing agent is within the above range, it is possible to obtain a high level of charging performance targeted by the present invention, as well as good spinnability, high strength of the nonwoven fabric, and advantageous in terms of cost.

The non-conductive polymer may further include other generally known additives such as a heat stabilizer and a weathering agent in addition to the additives.

The free fiber continuous charging step (S20-3) may be performed by continuously spraying the polar solvent together with a gas (eg, air).

When the polar solvent and the gas are sprayed together in the free fiber continuous charging step (S20-3), the fine dust removal rate and the fine dust removal performance maintenance rate can be improved compared to spraying only the polar solvent without gas.

In the polar solvent supply device, the polar solvent supplied to the spray nozzle in order to impart an electrostatic charge to the free fibers may be water, but is not limited thereto. The state of water may be mist particles, water droplets, water droplets, moisture, and the like. At this time, water is inexpensive and does not generate hazardous or harmful vapors when in contact with other materials.

In an embodiment of the present invention, the polar solvent is water, hydrogen peroxide, alcohols (isopropanol, ethanol, methanol, 2-propanol), ketones (methyl ethyl ketone ( methyl ethyl ketone), acetone), ethylene glycol, dimethyl sulfoxide, dimethylformamide, or a combination thereof.

The polar solvent may also have a dipole efficiency (dipole moment) of at least 0.5 Debye, more preferably at least 0.75 Debye, even more preferably at least about 1.0 Debye. The dielectric constant may be 10 or more, preferably 20 or more, and more preferably 40 or more. Polar solvents with higher dielectric constants tend to produce webs that exhibit greater filtration performance improvements.

Hereinafter, it will be described in detail that the free fiber continuous charging step (S20-3) has a heterogeneous or significant effect compared to the prior art.

(1) In general, as a method for electrostatic treatment during the melt blown process, as in US Patent No. 6,375,886, charging is performed through friction between a polar solvent and a filament being melt-spinning, as in US Patent No. 6,969,484. The melt-blown non-woven fabric was immersed in a polar solvent and charged through friction between water and non-woven fabric while water permeated through the non-woven fabric with a suction device. . As described above, the charging treatment method using a polar solvent requires a separate post-process of drying the polar solvent after the charging treatment, and therefore it is fundamentally impossible to laminate or composite the nonwoven fabric in a continuous process. U.S. Patent No. 6,375,886 and U.S. Patent No. 6,969,484 are incorporated herein by reference in their entirety.

(2) U.S. Patent No. 5,227,172 discloses a method in which a high potential difference is applied between a melt blown die and a collector so that the melt-spun resin is filamentized and inductively charged by the surrounding electric field. However, in this method, a melt-blown nonwoven fabric that has been electrostatically treated can be obtained without a separate post-processing treatment. However, since the non-woven fabric that has been inductively charged by the potential difference has a phenomenon that the charging efficiency is rapidly reduced depending on heat or the surrounding environment, it requires long-term storage in the sales process, such as a mask for removing fine dust, or with an air purifier filter. It has a disadvantage that it is difficult to apply it to a purpose where a long service life is guaranteed. U.S. Patent No. 5,227,172 is incorporated herein by reference in its entirety.

The present inventors spray a polar solvent together with air on the melt-blown nonwoven fabric layer in the form of a two-fluid body, and friction the polar solvent particles with sufficient kinetic energy with a small injection amount to the filament being melt-spun to have a high-efficiency triboelectric effect. We have developed a pretreatment device to do this, and it is characterized by not requiring a separate drying facility because it is sufficiently heated and evaporated by the heated air within the DCD (Die to collector distance) section due to a small injection amount. Due to these characteristics, it has the advantage of being able to combine the nonwoven fabric by continuous lamination in combination with the nonwoven fabric manufacturing process.

As for the components of the polar solvent, when the volume of the gas is 100 times greater than the volume of the polar solvent, the pressure of the polar solvent may be 0.5 bar to 10 bar, and the pressure of the gas may be adjusted to 0.25 bar to 20 bar. At this time, the polar solvent and the gas may be mixed in the injection nozzle.

The injection pressure of the gas may be 0.5-4 bar based on the injection pressure of the polar solvent of 1 bar. When the injection pressure of the gas is within the above range, the fine dust removal rate and the fine dust removal performance maintenance rate may be further improved.

In this case, the amount of the polar solvent sprayed from the spray nozzle per unit width (W) of the free fiber may be 20 (ml/min)/mm or less. Through this, the free fiber is well charged to the inside, and the amount of solvent used can be reduced compared to the same physical properties.

The nonwoven fabric obtained by electrostatically treating the melt blown nonwoven fabric is continuously polarized so that negative and positive charges exist semi-permanently, and this nonwoven fabric is referred to as an electret nonwoven fabric.

As described above, the method for manufacturing the composite nonwoven fabric may not include a separate drying step for removing the polar solvent sprayed in the free fiber continuous charging step (S20-3).

In addition, as described above, the polar solvent continuously sprayed in the free fiber continuous charging step (S20-3) is continuously heated by heated air within the DCD (Die to collector distance) section of the composite nonwoven fabric manufacturing apparatus. may evaporate.

The method of manufacturing the composite nonwoven fabric may further include continuously forming a second spunbond nonwoven fabric layer on the melt blown nonwoven fabric layer (S30).

The manufacturing method of the composite nonwoven fabric is the melt blown nonwoven fabric layer continuous forming step (S20) or the second spunbond nonwoven fabric layer continuous forming step (S30) on one or both sides of the melt blown nonwoven fabric layer after each spunbond The step of continuously thermocompressing the nonwoven layer (S40) may be further included.

In addition, by modifying the manufacturing method of the composite nonwoven fabric, a composite nonwoven fabric having various structures and/or configurations may be manufactured.

Another embodiment of the present invention provides a composite nonwoven fabric prepared by the method for manufacturing the composite nonwoven fabric.

Another embodiment of the present invention provides an article comprising the composite nonwoven fabric.

The article may be a mask for removing fine dust, a filter for an air purifier, or a filter for an air conditioner.

The article may include one or more of the composite nonwoven fabric. Specifically, the article may include only one composite nonwoven, or may include two or more composite nonwovens.

When the article includes two or more composite nonwoven fabrics, the article may be manufactured by laminating two or more composite nonwoven fabrics to each other by a method such as ultrasonic welding.

The composite non-woven fabric may include a first spun-bonded non-woven fabric layer, a melt-blown non-woven fabric layer, and a second spun-bonded non-woven fabric layer. Specifically, the composite nonwoven fabric may include a first spunbond nonwoven fabric layer, a meltblown nonwoven fabric layer, and a second spunbond nonwoven fabric layer, each of which is manufactured by a continuous process and integrated with each other.

The composite nonwoven fabric may include a pretreated melt blown nonwoven fabric layer. Accordingly, the composite nonwoven fabric may have a fine particle collecting function. However, since the conventional spunbond-meltblown multilayer nonwoven fabric has an average pore size of several to several tens of micrometers (㎛), there is little function of removing fine particles of 0.1 to 0.6㎛ level.

The composite nonwoven fabric may include the first spunbond nonwoven fabric layer, the melt blown nonwoven fabric layer, and the second spunbonded nonwoven fabric layer in this order. However, the present invention is not limited thereto, and the composite nonwoven fabric may include the first spunbond nonwoven fabric layer, the melt blown nonwoven fabric layer, and the second spunbonded nonwoven fabric layer in a different order.

The first spunbond nonwoven fabric layer and the second spunbond nonwoven fabric layer may each include a plurality of spunbond nonwoven fabric sublayers. Specifically, the first spunbond nonwoven fabric layer and the second spunbond nonwoven fabric layer may include a plurality of spunbond nonwoven fabric sub-layers that are each manufactured in a continuous process and integrated with each other.

The melt-blown non-woven fabric layer may include at least one pre-treated melt-blown non-woven sub-layer. Specifically, the meltblown nonwoven fabric layer may include only one pretreated meltblown nonwoven sublayer, or a plurality of pretreated meltblown nonwoven sublayers manufactured by a continuous process and integrated with each other. .

The melt-blown non-woven fabric layer may further include at least one non-electrostatically-treated melt-blown non-woven fabric sub-layer in addition to the at least one electrostatically treated melt-blown non-woven fabric sub-layer. Specifically, the melt-blown non-woven fabric layer includes at least one uncharged melt-blown non-woven fabric sub-layer in addition to at least one pre-treated melt-blown non-woven fabric sub-layer, or a plurality of melt-blown non-woven fabric sub-layers manufactured in a continuous process and integrated with each other. It may further include an uncharged meltblown nonwoven sub-layer.

At least one spunbond nonwoven fabric, at least one electrostatically treated meltblown nonwoven fabric and/or at least one uncharged meltblown nonwoven fabric included in the composite nonwoven fabric may each independently comprise a non-conductive polymer. .

The non-conductive polymer may be the same as the non-conductive polymer described in the related section on the manufacturing method of the composite nonwoven fabric.

The total content of the electrostatically treated melt blown nonwoven fabric in the composite nonwoven fabric may be 3 to 50 parts by weight based on 100 parts by weight of the total weight of the composite nonwoven fabric. When the total content of the electrostatically treated melt blown nonwoven fabric is within the above range, a composite nonwoven fabric having excellent filtration performance, shape stability and durability may be obtained.

The composite nonwoven fabric may have a basis weight (mass per unit area) of 10 to 500 g/m ² , for example, 20 to 100 g/m ² .

A plurality of nonwoven fabrics included in the composite nonwoven fabric may be integrated (ie, bonded) to each other by thermal fusion rather than ultrasonic fusion.

The composite nonwoven fabric may further include at least one additional layer.

As an example, each of the additional layers may include at least one separate nonwoven fabric that is neither a spunbond nonwoven fabric nor a meltblown nonwoven fabric.

As another example, each of the additional layers may include one or more layers made of a material other than the non-woven fabric.

1 is a view schematically showing a composite nonwoven fabric 10 according to an embodiment of the present invention.

The composite nonwoven fabric 10 according to an embodiment of the present invention includes a first spunbonded nonwoven fabric layer 11 , an at least partially charged melt blown nonwoven fabric layer 12 , and a second spunbonded nonwoven fabric layer 13 . do.

Hereinafter, the present invention will be described in more detail through examples. These examples are for explaining the present invention in more detail, and the scope of the present invention is not limited to these examples.

Example 1: Preparation of composite nonwoven fabric

A propylene homopolymer (LG Chem, H7900) having a melt index (MI) of 34 g/10 min was used as the polymer for forming the spunbond non-woven fabric layer (SB), and melt flow was used as the polymer for forming the melt-blown non-woven fabric layer (MB). A resin (LG Chem, H7910) having an index (MFR) of 1000 g/10 min was used. In addition, Chimasorb 944, a hindered amine light stabilizer, was added to the polymer for forming the melt blown nonwoven fabric layer (MB) in an amount of 0.5 wt%. Thereafter, a composite nonwoven fabric in the form of spunbond-meltblown-spunbond (SMS) was continuously manufactured using an apparatus for manufacturing a composite nonwoven fabric as shown in FIG. 2 . Specifically, the melt blown non-woven fabric layer (MB) is continuously charged by contacting with water (injection pressure: 1 bar) together with air (injection pressure: 2.2 bar) through a two-fluid nozzle in the apparatus for manufacturing the composite non-woven fabric. It is laminated on the spunbond nonwoven fabric layer SB, and another spunbond nonwoven fabric layer SB is laminated on the melt blown nonwoven fabric layer MB. As a result, an SMS nonwoven fabric laminate was obtained. Thereafter, the SMS nonwoven fabric laminate was manufactured in the form of a single composite nonwoven fabric through a thermocompression bonding process between a roll having an embossed pattern and a roll having no irregularities. Here, the total basis weight of the SMS composite nonwoven fabric ^{was adjusted to 100 gsm (g/m 2} ), and the basis weight of the melt blown nonwoven fabric layer (MB) was adjusted to 22 gsm.

Example 2: Preparation of Composite Nonwoven Fabric

An SMS composite nonwoven fabric was prepared in the same manner as in Example 1, except that the air injection pressure was changed to 0.5 bar while the water injection pressure was maintained at 1 bar during the production of the melt blown nonwoven fabric layer (MB).

Example 3: Preparation of Composite Nonwovens

An SMS composite nonwoven fabric was prepared in the same manner as in Example 1, except that the air injection pressure was changed to 4 bar while the water injection pressure was maintained at 1 bar during the preparation of the melt blown nonwoven fabric layer (MB).

Example 4: Preparation of Composite Nonwovens

An SMS composite nonwoven fabric was prepared in the same manner as in Example 1, except that the air injection pressure was changed to 0.3 bar while the water injection pressure was maintained at 1 bar during the preparation of the melt blown nonwoven fabric layer (MB).

Example 5: Preparation of Composite Nonwovens

An SMS composite nonwoven fabric was prepared in the same manner as in Example 1, except that the air injection pressure was changed to 4.5 bar while the water injection pressure was maintained at 1 bar during the preparation of the melt blown nonwoven fabric layer (MB).

Comparative Example 1: Preparation of composite nonwoven fabric

Except for changing the air injection pressure to 0 bar while maintaining the water injection pressure at 1 bar during the production of the melt blown nonwoven fabric layer (MB) (that is, only water is sprayed and air is not sprayed), the above embodiment An SMS composite nonwoven fabric was prepared in the same manner as in 1.

Comparative Example 2: Preparation of composite nonwoven fabric

During the production of the melt blown nonwoven fabric layer (MB), the water jet pressure and the air jet pressure were changed to 0 bar, respectively (that is, changed so as not to spray water and air), and the melt blown nonwoven fabric layer (MB) was manufactured in the US Patent No. An SMS composite nonwoven fabric was prepared in the same manner as in Example 1, except that it was charged by the charging method disclosed in No. 5,227,172.

Comparative Example 3: Preparation of non-woven fabric laminate

Two spunbond nonwoven fabric layers (SB) and one meltblown nonwoven fabric layer (MB) were separately prepared, and then laminated to each other to prepare an SMS nonwoven fabric laminate. Here, the melt blown nonwoven fabric layer (MB) was charged by the charging method disclosed in US Patent No. 6,375,886. Also, in the same manner as in Example 1, the total basis weight of the SMS nonwoven laminate ^{was adjusted to 100 gsm (g/m 2} ), and the basis weight of the melt blown nonwoven fabric layer (MB) was adjusted to 22 gsm.

Evaluation example: evaluation of physical properties of nonwoven fabric

The fine dust removal rate, the fine dust removal performance maintenance rate and the need for a separate drying process of each of the composite nonwoven fabrics or nonwoven fabric laminates prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated in the following way, and the The results are shown in Table 1 below.

(1) Measurement device: TSI-8130 model of TSI was used.

(2) Formation of aerosol: The measuring device evaporated water after contacting an aqueous sodium chloride solution with air to form an aerosol containing sodium chloride dispersed in the air with an average particle diameter of 0.3 μm and a sodium chloride particle concentration of 18.5 mg/m ³ . .

(3) Evaluation of aerosol removal efficiency: The aerosol permeation flow rate was 95 L/min, and the evaluation area of the nonwoven fabric was 100 cm ² . Here, the aerosol removal efficiency was recorded as the fine dust removal rate.

(4) Evaluation of the need for a separate drying process: Before the composite nonwoven or nonwoven laminate is fed from the screen belt to the calender roll, the water content in the composite nonwoven or nonwoven laminate is measured, and if the result is below the reference value (1.0 wt%), separate The drying process was recorded as unnecessary, and if the result exceeded the standard value (1.0 wt%), a separate drying process was recorded.

	Example					comparative example
	One	2	3	4	5	One	2	3
Removal of fine dust before use (%)	98.5	96.7	98.3	94.1	94.9	82.3	54.5	91.5
Fine dust removal rate (%) after 8 hours of continuous use	93.5	92.1	93.3	89.5	89.7	76.5	30.6	85.9
Fine dust removal rate (%) after 300 hours of continuous use	89.2	88.0	87.9	84.6	84.9	69.4	19.8	83.3
Whether a separate drying process is necessary	Unnecessary	Unnecessary	Unnecessary	Unnecessary	Unnecessary	necessary	Unnecessary	necessary

Referring to Table 1, the composite nonwoven fabrics prepared in Examples 1 to 5 were excellent in all of the fine dust removal rate before use, the fine dust removal rate after 8 hours of continuous use, and the fine dust removal rate after 300 hours of continuous use, as well as a separate The drying process was also found to be unnecessary.

However, the composite nonwoven fabric prepared in Comparative Example 1 and the nonwoven fabric laminate prepared in Comparative Example 3 were excellent in the fine dust removal rate before use, but both the fine dust removal rate after 8 hours of continuous use and the fine dust removal rate after 300 hours of continuous use were low. In addition, it was found that a separate drying process was also required.

In addition, the composite nonwoven fabric prepared in Comparative Example 2 had an excellent fine dust removal rate before use and a separate drying process was not required, but both the fine dust removal rate after 8 hours of continuous use and the fine dust removal rate after 300 hours of continuous use were low.

Although the present invention has been described with reference to the drawings and embodiments, it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (9)

1. Continuously forming a first spunbond nonwoven layer (S10);

   continuously forming a melt blown nonwoven fabric layer on the first spunbond nonwoven fabric layer (S20); and

   and continuously forming a second spunbond nonwoven layer on the melt blown nonwoven fabric layer (S30),

   The melt blown nonwoven fabric layer continuous forming step (S20),

   Continuously forming free fibers with a non-conductive polymer (S20-1),

   Continuously spinning the free fiber (S20-2),

   Continuously charging the free fibers by continuously spraying a polar solvent on the free fibers (S20-3) and

   A method of manufacturing a composite nonwoven fabric comprising the step (S20-4) of continuously integrating the free fibers to continuously form a nonwoven fabric.
2. According to claim 1,

   The free fiber charging step (S20-3) is a method of manufacturing a composite nonwoven fabric that is performed by continuously spraying the polar solvent with a gas.
3. 3. The method of claim 2,

   The injection pressure of the gas is 0.5 to 4 bar based on the injection pressure of the polar solvent of 1 bar.
4. According to claim 1,

   A method for producing a composite nonwoven fabric that does not include a separate drying step for removing the polar solvent sprayed in the free fiber continuous charging step (S20-3).
5. 5. The method of claim 4,

   The polar solvent continuously sprayed in the free fiber continuous charging step (S20-3) is continuously heated and evaporated by heated air within the DCD (Die to collector distance) section of the composite nonwoven fabric manufacturing apparatus. Way.
6. According to claim 1,

   After the melt-blown non-woven fabric layer forming step (S20), the first spun-bonded non-woven fabric layer, the melt-blown non-woven fabric layer and the second spun-bonded non-woven fabric layer are continuously thermocompression-bonded (S40) Composite further comprising A method for manufacturing a nonwoven fabric.
7. A composite nonwoven fabric manufactured by the method for manufacturing a composite nonwoven fabric according to any one of claims 1 to 6.
8. An article comprising the composite nonwoven according to claim 7 .
9. 9. The method of claim 8,

   The article is an article that is a mask for removing fine dust, a filter for an air purifier, or a filter for an air conditioner.

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